Mining machine



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c. E. DAvls MINING MACHINE 6 Sheets-Sheet 3 Filed June 5, 1922jaa/72270:- /erg if@ IIII'IIIIIHIA:

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' April 3, 1928.

1,664,666 C. E. DAVIS MINING MACHINE Filed June 5. 1922 6 sheets-s116664y April 3, 19213.`

c. E. DAVIS MINING MACHINE Filed June 5. 1922 6 Sheets-Sheet v5IIIIIIIIIIIHIHIIIIH Ag lll.

vApril 3, 1928. 1,664,666

c. E. DAvls MINING MACHINE Filed June 5. 1922 s sneets-sngt e lPatentedApr. 3, 1928.

UNITED STATES PATENT oi-Fice CHARLES .'E. DAVIS, OF CHICAGO, ILLINOIS,ASSIGNOR IO GOODMANk MANUFACTKURP ING COMPANY, OF CHICAGO, ILLINOIS,CORPORATION OF ILLINOIS.

Y'irriniive MACHINE,

Application med June 5, v1922. seran No. 566,154.

This inventionrelates to improvements in lierf cutting mining machinesparticularly adapted for use in the room and pill-ai system of mining,although also adapted for use in other systems of mining, as forinstance the longwall or panel systems.

The principal object of this invention is to provide a new and improvedmachine' of` the character described having power actuated tractiondevices capable of propelling the machine along the ground, both for movving from place to place in the mine and for guiding and controlling they the workingface to cut a continuous lrerf.

In carrying outmy invention, I utilizey as the principal features of mymachine, a body portion provided witha swivelled cutting element and avplurality of power actuated traction devices adapted'to support andpropel the machine andcutting` element. rEhe cutting element comprises acutter bar which is swivelled centrally of the machine,

and is adapted to beautomatically swung in a substantiallyhorizontalplane'into various positions with respect to said body portion. rThetraction devices are arranged so that one or more may be raised topermit the Vcutter bar to move thereunder and thereafter may be returnedinto supporting` engagement with the ground under certain conditions aswill hereinafter appear. Auxiliary supporting means for. the bodyportion are also provided to afford stability to 4the machine when oneor more of the traction ldevices is out of supportingengagement with theground. .Means are also provided when desirable whereby a flexible draftrope or its equivalent may be used to assist in feeding the machine tothe coal.

The invention may vbest be understood by reference to the accompanyingdrawings in which Figure 1 is a plan view of amachine einf bodying thevarious features of my invention.

Fig. 2 is a view in side elevatiouof the machine shown in Fig. 1 withportions thereof broken. away to show details of the operatingmechanism.

Fig. 3 is an end view of the machine lool@ ing from the riO'ht of Figs.1 and 2, with a portion of the mechanism for swivelling the .cutter barShown in section.

machine along bearing ring 15a, as shown in Fig. 6.

F'g. el is [a longitudinal cross-section of the machine taken on line 1-4 of Fig. 1.

Fig. 5 i-s a detail in horizontal cross-section taken on line 5`5 ofFig. 3.

Fig. 6 isa transverse cross-section taken onk line 7--7 of Fig. 2 drawnto a somewhat larger scale than the preceding iigures.

Fig. 7 is a transverse cross-section taken :on line 8%-8 of, Fig. 2shown in the rsame scale as Fig. 5.

Fig. 8 .is a detail in perspective showing the elevating mechanism forthe traction devic at one side of the machine. y

9, 10 and 11 are details showing parts ofthe power transmission gearing.

'Figs 12,713, lll, 15 and 16 are diagrammatic views showing the machinein various positions'duringl the cutting operation.

Fig. 17 isa diagrammatic view showing the application of supplementaldraft means tothe machine.

Referring now to details of the kembodiment illustrated in the drawings,10 indicates a main frame ony which is mounted a motor casing 11enclosing a suitable prime mover such as an electric motor. The machineis supported on a plurality of traction devices, preferably comprisingrotatable wheels v12, 12 with traction studs of yany Vsaid wheels arefour in number and positioned at the corners ofthe machine'. 13indicates a cutter arm-which is provided with Y ari-.endless cutterchain 13l of the usualconstruction. l In. the fo "m of my inventionillustrated, this cutter arm .is pivotally mounted under the centralportion of the mainframe 10 and arranged to cut a llrerf I near the minefloor. The inner end of said cutter arm is supported on a'suitablebracket [14, which depends from ahorizontally disposed turntable 15rotatably mounted on an annular portion 10a forming a partof the mainframe 10 and retained thereon by a etails of the mechanism for operatingthis turntable will hereinafter appear.

An auxiliary supporting device preferably comprising a pan 16 is mountedunderneath land spaced 4,fromfthe turntable'l and rigidly connectedltherewith by' suitable supports 17, 17.' This pan preferably extendslaterally under the vinner endof thecutter cated in dotted lines in Fig.2.

arm as shown in Fig. 4. Under certain conditions, it adapted to rest insliding and supporting engagement with the. ground. The lateral margins18, 13, of the pan 16 are preferably turned iupwardly, as shown, so thatvthe pan may readily move ovei uneven floor. The pan is open on allsides, however, so as to permit the cuttings carried rearwardly by thecutter chain 13a to be readily discharged therefrom.

Tn oi'der to allow the cutter arm to be swung from a position in whichit extends from one end. of the machine as shown in Fig. 12 to aposition in which it extends from the side of the machine such as inFig. 15, l provide means for ten'i'iorarily raising the wheels 12, 12,so as to allow the cutter arm to pass thereunder, and thereafter saidwheels may be lowered again into engagement with the ground. In the formof machine illustrated, l have elected to show one in which the cutterarm may be swung on all sides of the machine, and to this end all fourof the wheels 12, 12, are provided with means actuated by the motorwhereby they may be raised and lowered. The arrangement is such thateachwheel may be actuated independently of the other wheels.

The mechanism for raising and lowering the wheels with respect to theframe will now be described in detail. Referring first to the wheelwhich appears adjacent the motor casing 11 in Fig. 2, it will be seenthat this wheel has its aXle 20 journaled at the outer end in an arm 21and at the inner end in an ai'm 22 (see Fig. 8). These arms arepivotally mounted 0n a transverse shaft 23 mounted at the side ofthemain frame-10. A pair of upright actuating arms 24, 24, are connected tothe pivoted end of the arm 21. In the preferred form, aiins 24, 24, areintegral with arm 21 as shown and form therewith in effect a bell cranklever by which the wheel may be pivotally swungI about the shaft 23to-be raised and lowered as indi- Tlie upper end of the arms 24, 24, areactuated by mechanism driven by the motor, which in the embodimentillustrated comprises a longitudinally disposed screw member 25 havingone end in threaded engagement with a worm gear 26 and having itsopposite end enlarged as indicated at 27,and extending into ahorizontally disposed guide block 23 carried on the frame. A pair ofpivoted links 29, 29, connect end portion 27 of screw 25 and the ends ofthe arms 24, 24. The

worin gear 26 is mounted on a support 30l and is meshed with a worm 31mounted on a transverse shaft L32. This worm 31 has operative connectionwith the motor through the following` gear train which will now betraced beginning with the motor 11. Referring to Fig, 4, it will 4beseen that the motor driving pinion 35 drives a gear 36 on ashaft 37which extends centrally and longitudinally to one end of the machine. Aworin 38 on this shaft drives a worm gear 39 carried on a shaft 4()arranged above and at rright angles to the shaft 37. The drivingmechanism on the two sides of the machine being. similar, as before setforth, the same mechanisms indicated wi-ll be duplicated on oppositesides of the machine. A reversing clutch 41 of a usual typel isfeathered on the shaft 40 between a pair of oppositely disposed mitregears 42, 42, both of which are meshed with a mitre gear 43. This clutchmay be thrown into engagement with one or the other of the mitre gears42, 42, so that the gear may be driven in either direction,

these devices is the shaft 45 carrying the mitre gear 43 just mentioned.A sun gear 46 is keyed on the shafty 45 and ismeshed with aplanetary'gear pinion 47 rotatably mounted in a cage 48.` There may be aplurality of such planetary gear pinions, as desired. The cage 43comprises a pair of oppositely disposed plate members 43 and 48"connected by a bolt 48 or the like and rotatably mounted on the shaft onopposite ,sides of the sun gear as shown in Fig. 9. The

outer periphery of planetary pinion 47 is meshed with an internal gea-rcarried by` a casing 49 mounted free to rotate with respect to the otherportions of the transmission device. Adjacent the planetary pinion 47and uiiitai'y therewith is a. planetary pinion 50 of aflesser pitch.diameter. This planetary pinion 50 is meshed with an internal gearcarriedby a driven member 51. A gear member 52 is mounted to rotatevwith driven member 51. A friction band 53 of any suitable constructionis mounted on the casing 49 and is provided with a handle53", by whichthe rotation of said casing 49 may be controlled under certainconditions as will hereinafter more fully appear. Means also providedfor locking the cage 43 against rotation which comprises alongitudinally movable gear segment 54 adapted to engage a. toothedperiphery 55 formed integral with the outer plate 43a of said cage. InFigs. 10 and 11 it will be seen that each of the two planetarytransmission devices are provided with locking devices Y54, 54,

supported on the frame and movable inde-` inea-,cee

at low speed, the locking member 54 is thrown out of engagement with thegeared periphery 55 of the cage 48 so as to allow said cage to rotatefreely. Friction band 53 on the casing 49 is tightened so as to restrainsaid casing from rotation. The planetary gears will, when driven by thesun gear, rotate about thev axis of the latter. The planetary gear 50,which rotates on its own axis with the gear`47, is meshed with theinternal gear member '51, b-ut being of less pitch diameter than thegear 47, the internal gear member 51 and driven gear 52 are rotated at agreatly reduced speed. This reduction in speed depends upon thedifference in pitch diameters of the planetary gears 47 and 50.Variation in driving` speeds may be obtained by loosening the frictionband 53 so as to allow the casing 49, which is under a constant torquecaused by the pinion 47 meshed therewith, to rotate slowly in theopposite direction. rllhis will cause a proportionate reduction in theeffective driving speed transmitted to the driven gear 52. lf thefriction band 53 is entirely released, the casing 49 will rotate freelyand no driving torque will be transmitted to the gear 52.

`When it is desired to drive at high speed, the locking member 54 isengaged with the toothed periphery 55 of cage 48 so as to restrain saidcage from rotation. The friction band 53 is released and the sun gear 46then drives the gear 52 through the medium vof planetary gear members 47and 5() and internal gear member 51. Through this driving connectionthere is a slight gear reduction in driving speed, but not nearly asgreat as the reduction caused at low speed in which the cage 48v is freeto rotate as has been above described.

From the above description it will be seen that each of the planetarydevices 44, 44,

'provides variable speed transmission to the driven members'52, 52. Atlow speed the cage 48 carrying the planetary gears is free to rotate,and a wide variation in effective driving speeds varying from zero tothe maximum of the low speed gearing may be provided by varying thetension on the brake band 53 which controls the rotation Aof the casing49. At high speed the cage 48 is locked against rotation and there is arelatively slight reduction in the driving speed between. driving member45 and the driving gear 52.v

The driven gear is meshed with a'gear 5G keyed on a longitudinallydisposed shaft 57. A bevel gear 58 on said shaft is meshedL with a bevelgear 59 on a. transverse jack shaft 60 (see Fig. 7 and Fig.'9). A gear6l is mounted to rotate with bevel gear 59 and drives the gear 627on thetransverse shaft 32 which carries the worm 31 associated with worm 26 ofthe elevating mechanism heretofore described. A sliding clutch 64 isfeathered on said shaft and is adapted to throw the elevating mechanisminto and out of engagement with the motor. From the foregoingdescription it will be seen that the wheels may be raised or lowered atwill by engaging-clutch 64 with worm 31 and setting the reversingvclutch 41 to drive in the direction desired. The clutch 21 willmanifestly be moved at a slow speed, as it is actuated through theseveral gear reductions described.

Mechanism of similar nature is provided for raising and lowering theother wheel of the pair at one side of the machine. The bell crank lever`69 connecting the second wheel with the frame is provided with an upperarm 70 which, in the present construction, is curved in order to avoidinterference with the shaft 32, as shown in Figs. 2 and 8. This arm isactuated by a screw member 71 threaded at one end in a worin gear 72 andsupported at the other end in a guide block 73. vThe screw member isconnected to the arm 70 by a single pivoted link 74. The worm gear 72 isactuated by a worm 75 through clutch 7 6 on the shaft 312.

The mechanism for controlling and driving the traction wheels 12, 12,also has operative connection with the motor 11. Each pair of wheels atone side ofthe machine is preferably driven and cont-rolled as a unit,and in the form shown, these units are similar, so that a description ofthe mechanism at one side will serve to show the construction andoperation of both of said units.

From the foregoing description it will appear that gear 59 on transverseshaft GO is adapted to be reversibly actuatedv at various speeds throughthe transmission device 44. A drive gear 8O is also mounted on shaft d0and has a toothed periphery 81 adapted to engage a rack 82 arrangedabout the periphery of one of the wheels 12. The gear 8O is furthermeshed with an idler or lreach gear 83 on shaft 83"L which in turn ismeshed with a gear 84 mounted on the shaft 23. The gear 84l is meshedwith the raclr85 formed en the periphery of tl e opposite wheel 12 atthe motor end of the casing. The driving gears 8O and 84 are thus drivenin unison', and in the same direction. Said driving gears are alsomounted concentricl with their respective wheel supporting arms G9 and21, so that they are .in driving engagement with their respective wheelsin all positions of the latter. Driif'ing gears 8O and 84 may be throwninto and out of operative connection with' the motor oy means of ashifting clutch 88 feathered on the huh portion 87 of the driving gear59.

A brake for controlling each of the driving units is provided whichcomprises a drum 88 keyed on idler gear 88Vand having means such as twooppositcly acting worin devices 89a, 89a, associated with an operatinghandle 89", adapted to extend laterally trom the side ot the inacaine inposition to be readily controlled by the operator.

The mechanism tor actuating the cutter chain is Ishown in Figs. 1 and 6.A bevel pinion 90 is carried on the shatt 37, which has already beendescribed as being operatively connected to the motor 11 through thegear o6 and armature pinion 35. 'l'he bevel pinion 90 is meshed with ahorizontally disposed bevel gear 91 mounted on a vertical shaft 92extending concentricaliv through the turntable 15 which supports thecritter arm. A clutch ring 93 is mounted on said shaft and is adapted tobe engaged by a. plurality of clutch members 94. 94, carried by avertically movable clutch sleeve 95 and adapted to ex'end throughapertures 96, 96, in the gear member 91 to engage the clutch jaws 97,97, carried by said clutch ring` 93. A chain driving` sprocket 100 ismounted at the lower end ot the shaft 92, and is adapted to drive thecutter chain supported on the cutter bar. vBy means ot' the arrangementjust described, the cutter' chain may be connected to the motor ordisconnected theretrom by means ot the clutch 95 and may be driven ineither direction, it desired, by reversing the direction ot rotation otthe motor in the usual manner.

lThe mechanism it'or swingingl the turntable and cutter arm carriedthereby coinprises a gear 110 (see Figure 2) rotatably mounted at theouter end ot the shatt 37 and adapted to be clutched to said shatt bysuitable ineans such as a cone clutch v111. A gear 112 on the end ot alongitudinally disposed shaft 113 is driven by gear 110 through an idlergear 114-. The shaft 113 entends forwardly underneath the motor casing11 and has a worm 115 thereon which engages a worm gear 116 mounted torotate on a verticalanis. This worin and worm gear is preferably ot theself-locking type, that i-s to say, the pitch ot worm 115 is such thatthe associated mechanism for driving the turntable 15 is locked againstrotation unless positively driven by the motor. By means ot thisarrangement, the turntable and cutter arm carried thereby may be lockedin any desircdposition, as tor instance, when the cutter arm isextending laterally troni Ythe tra/nie in position to make a cut alongthe working tace as shown in Fig. 15.

In order that the turntable may be ro vtated at a relatively slow speedsuitable for teeding the cutter arm to the coal, gear re ductionmechanism is provided, as tor instance, a planetary transmission device,de tails ot which are shown in Figs. 3, 4t and 5. A casing 117 isintegral with the main iframe 10 and has a centrally disposed stud 118in which is journaled a shaft 119. The driving worm gear 115 has anupwardly `extending hub portion 120 journaled about this stud andprovided at its upper end with a pinion 121 which terms the `sun gear otthe planetary. A plurality ot planetary gears 122, 122, are rotatablymounted on studs 123, 123,

carried by a plate 1211 fixed to the casing 117.

rlhese planetary gears are nieshed at their inner peripheries with thesun gear 121 and at their outer peripheries vwith the internal gear 125carried by a gear member 126 which is keyed to the upper end ot shatt119. A cover 127 provided to enclose the top ot the casing 117 andprovide bearing for the upper end ot shaft 119 and gear member 126. Adriving pinion 130 is carriedat the end ot the shaft 119 which extends'through the Casing 117, said pinion being meshed with the .toothedperiphery 131 et' the turntable 15.

By means ot the planetary mechanism ust described, the turntable 15, maybe rotated by power to swing the cutter arm into any desired angularposition and to feed the cutter arm to the coal.

Under certain working conditions, as for instance when the cutting ishard and the mine tloor is ot such a nature that suiticient traction yisnot afforded to the traction wheels, means supplemental to the tractiondevices may be provided for teeding or controlling the machine,comprising a draft rope 1410, indicated in dotted lines in F ig. 1 andin tull lines in Fig. 17. This draft rope maybe detachably connected tothe periphery of the wheel by any suitable means,

such as a hook 1111 at one end voit the rope having engagement in asuitable aperture 142 `formed in the periphery ot theV wheel, as shownin Fig. 1. The tree end ot the rope is anchored as indicated at 143 inFig. 17 and the ropel is then wound upon thewheel adjacent the rack 82as themachine advances. By means of this arrangement the rate o1advanceot the machine caused by the dra-ft rope 140 will be equal to thenor* mal peripheral speed ot thewheel 12 to which the draft rope isattached.

In Fig. 17 it will benoted that the draft rope 140 is applied to theforward wheel adjacent the working face ot the mine and is acting tofeed the machine to the coal. 1t is obvious that a similar draft ropamay be attached to the other wheels, as rfor instance under certainconditions, such as will hereinafter appear, in which it may bedesirable to utilize such a rope in connection with one et the wheels onthe opposite side ot' the ktrame and extending in a direction oppositeto that in which the machine is moving.

In order to tacilitate transportationV otV the machine overV tracks inthe entries, I

provide the wheels 12, 12, with iianges 1115 for engaging the track inthe usual manner. rllhese flanges are preferably placed adjacent theracks 82 and 85, so as to prevent the cable 140 from being accidentallyinjured by the drive gears 8() and 811, respectively, when said cable,is applied to the periphery.

The use andl operation ot a cutting inachine constructed as abovedescribed may best be described in connection with the dia-` gramsappearing in Figs. 12 to 17, inclusive.' f Y The machine is normallysupported by the traction wheels 12, 12, which ar-e power ac tuated soas to propel the machine from place to place in the mine andare iiangedto be guided yon the mine tracks, when desired. `Wliile being movedalong the entry or into the room preparatory to cutting, the tractionwheels are preferably positioned at their` lowest position respective tothe main trame, as shown in Fig. 1, so as to provide clearance for theauxiliary supporting pan16 and the cutter arm 13. Said cutter bar 13 isarranged longitudinally of the inacliine while being so transported. Themachine is capable ot being steered when operating on the mine ioor,inasmuclrasltwo pairs ot traction wheels at the oppositesides of thetrame are adapted to be driven at diferent 'speeds' and controlledindepend-I ently of each other through the two setsotcontrolling'mechanisms on opposite sides oit machine may thus be guidedto the place wher-e it is desired to make a cut. The machine isparticularly adapted tor use in the room and pillar system of mining inwhich the working tace at one end of the room is advanced by makingsuccessive transverse cuts trom one side or ri.b-ot thev room to theother. Referring now to Fig. 12, the'machine is shown as moved intoposition. at one corner of a'room,with the macliine'parallel to theworking tace'indicated at 150 and with the cutter arm extending from oneendthereof into Contact with the right hand wall or rib 151. In thisposition the machine is sumped, that is to say, it is given its initialcut into the worli g lare.

As is theV case with the reoni and pillar systeni ot mining, it isdesirable to extend the lateral walls of theroon'is'in a substantiallystraight line and to this end myv machine is suinped inv the followingmanner. The machine is lowered on the supportingwheels until Athe cutterarm 13 is vat the desired height trom the floor, and the pan 16 is insubstantial engagement with the ground.

rlie cutter chain 13 on the lcutter arm 13 is put into opera-tion andthe turntable 15 is then rotated so as to swing the cutter arm aboutits' aXis'to feed'the cutter arm to the n coal as shown in Fig. 13.Simultaneously, the traction devices are driven slowly to advance themachine bodily to the right and toward therib 151,y so thatv during themovement of the machine from t-he position wheels has been hereinbetoreshown in Fig. 12 to Fig. 13, the outer end of the cutter arm is movedsubstantially in alignment with the Wall 151. lVhile this cuttingmovement is taking place, it is necessary to lift the traction Wheel 12appearing at the upper right hand corner of the ma'- cliine in Fig. 12,so as to permit the cutter arm 13 to swing thereunder. Mechanism forraising this wheel independent-ly of the other described. lVhile themachine is being supported and propelled on the three wheels remainingin contact with the ground, iroper equilibrium is provided by means ofthe auxiliary support or pan 16 lwhich is normally adapted to havesliding contact with the ground and moves with the cutter arm. Thissupporting pan 16 is arranged to extend beyond the center of gravity ofthe machine so thatfthe equilibrium of the latter is maintained at alltimes. i Furthermore, while one of the wheelsr ing cut, so that undermost conditions,this v reaction of the cutter bar Vis sui'iicient tostabilize the machine irrespective'of the support afforded by the pan16.

In Fig. 14: the sumping cut is shown as completed and the machine bodyhas been moved to the right into close proximity with the right wall151. rlhe cutter arm extends almost at right angles with thelongitudinal axis of the machine. From this position the cutter arm maybe urtherrotated into a substantially right angled position with respectto the machine` as shown .in Fig. 15.A The raised wheel 12 Ymay then vbelowered into itsv normal supporting en- '.gagement with the ground..Thereafter the entire machine is propelled along the wall to leut acontinuous hert, as indicated in Fig. 15, with the cutter arm lockedagainst piv etal movement by reason.otr-the",self-lochA ingf7 worin geardrive associated vwith the turntable, as hereinbeiiore described.

During the transverse cutting movement illustrated in Fig. 15,`tliere isan enormous pressure on the cutter arm as it is being 'lied to the coal,which tendsl to twist the machine out ot'parallelisin with the workingtin That is to say, the outer side of the machine which is farthest awayfrointhe workingl face has a tendency to advance faster than the innerside.

sidesot' the frame are independently controlled in such a manner as tomaintain the machine in the desired angular postion with respect totheworking face. In order to `accomplish this purpose, the f traction unitnearer the mine wa-llis used primarily as the feeding means, that is tosay, it is driven at In order to overcome this tendency, the twotraction unitsat opposite the desired feeding speed, while the oppositeor outer unit is controlled so as to counteract any tendency to twistthe machine. The

`outer traction unit is therefore utilized to retard the movement of theouter side lrespective to the inner side. VThe amount of retardationnecessary will obviously vary greatly according to cutting conditions. Iior this purpose, various methods of con. trolling the retarding unitmay be used, depending upon working conditions. The pieferred method ofcontrol is to disconnect the outer traction vunit from the motor by.throwing out clutch 86 associated therewith, and then control thev brakeband 89 manually by means of the handle 89". This brake is operativethrough the idler or reach gear 88 which di'ives gears 82 and 811-, toretard f the forward movement of the twowheels 12,

. the outerunit will be positively driven at a slightly lower speed thanthe inner unit, and

there will be a resulting drag on the outer unit, which tends to retardthe latter with respect to the inner or feeding unit. rllhe outer unitmay also be reversed to drive in an opposite direction with respect tothe feeding unit, it' desired, by n'ieans'of the reversing mechanismdescribed.

Under conditions where sufficient traction for feeding the machine tothe coal cannot be secured a su lemental draft device 140 7 l may beconnected with one of the inner trac-y tion wheels 12 in themanner,hereinhefore set forth in connection with the description ofyFig. 17. Under these conditions also, the outer traction unit may beutilized as a retarding device and ordinarily will be sutilcienttomaintain the desired angular po* sition with respect tothe wall, but.under extraordinary conc'iitions, a second cuoio ma y be used inconnection with one of the wheels of the retarding unit and trained in adirection opposite to the feeding cable 140.

fis the machine approaches the end ot' the cut at the left hand side ofthe room shown in Fig. 1G, the cutter arm and turntable are againactuated and swung at an angle to the machine until the outer end of thecutter arm is substantially in alignnient with the left hand wall 1F Q.The finishing cut is then made by lifting the wheel 12 appearing in theupper left hand corner ofA the machine in Fig. 1G so as to allowtheicutter arm to swing thereunder, while the machine is simultaneouslymoved bodily to ther-ight so that the cutter arm finishes the cut inalignment with the wall 152, as indicated in dotted lines in thisligure. The machine is then withdrawn from the room and moved to thenext place to'be cut.

So far as the general features of my invention are concerned, it isobvious that the machine might be successfully used for most purposes ifconstructed` to cut at one side only, that isto say, if the cutter armwere limited to swing only from one end to the other through an arc of1809. In this. case,

.the inner traction unit on the cutting side would manifestly beutilized mainly as a feeding element, and the outer traction unit wouldbe utilized mainly as ai retarding element. A machine ofv this charactercouldy be constructed somewhat simpler than the formV both sides of themachine and provided with duplicate, independently controlled tractionunits. vThis reversibility feature 'may be eX- plained as follows:Inmaking the one cut across the. face illustrated in Figs. 12 to 16,

the cut-ter arm swings through an arc ofV approximately 180.. In theinitial position shown in Fig. 12 the. cutter arm extends from the endadjacent the motor 11, and in Fig. 16 it extends from the oppositel end.@wing to the construction of the machine, by which the cutter arm has arangeofBtOO, vand the traction units on opposite sides of the machinebeing similar, the initial'or sumping cut maybe made from either end, sothat when one cut is completed, as for instance as shown in. Fig.` 16,the machine may then be moved tothe next cutting place in a. reversedposition, i. e. turned end-to-end with respect to i s position instarting the last cut. Therefore, with the preferred form shown, itisnot necessary to return thev cutter arm to its initial position for eachcut, but the machine may be moved to the next. cutting place and bepresented lto the work with the side which was previouslyv the outerside placed adjacent the working face. In making the next cut, thetraction unit which rwas previously the feeding unit then Vbecomes theretarding unit, and vice versa', and the cutter armV swings throughapproximately 18,0c at the other side of the machine. Vhen operated inthis `manner, the. cutter arm moves in a complete circle Vfor every twoLcuts. i

The machine may be used advantageously in various systemsf of mining, as.f0r,1nstance,

the longwall'or panel systems or for cutting ent-ries, inasmuch as it isreadily propelled and guided and is capable of cutting either at the endor at the sides thereof.

Among the principal advantageous features of my invention is theprovision of a unitary structure, including the cutting element andpropelling and guiding mechanism therefor, which may be moved over themine floor Withoutrequiring tracks, such as are necessary With cuttingmachines of the overcutting or arc-Wall type, or of a track supportedtruck such as are used for transporting continuous cutting machines ofthe shortv/all type.A 'l' he machine fui'ther recommends itselfparticularly for use Where the coal is to be gathered by a scraper ordrag line system, in Which it is undesirable to have tracks extendinginto the mine room or adjacent the Working place.

Another novel feature of myV invention is the application of a tractionunit for use as a retarding device on a laterally movable cuttingmachine. As far as the broad aspect of this feature is concerned, it isobvious that the power for advancing the machine laterally to feed it tothe coal may be applied to the inner side of the machine by any means,such as a traction unit as in Fig. l5, or by the sole means of aflexible draft device, in the manner suggested by thev modified formillustrated in I? ig. 17. Such a retarding traction device is thereforenot limited to a traction-fed cutting machine, but can be applied toother types of machines, as for instance to cable-fed machines of thevfell known types of continuous cutting or shortwall machines. Thistraction unit includes a brake or its equivalent for controlling thespeed of the retarding traction unit, and also is provided withreversible driving connections with the motor, independent of thefeeding means, for positively swinging the outer end of the machine ineither direction with respect to the inner or feeding end.

Although I have shown as apreferred construction. a single mot-or havingoperative connection with the various n'iechai'iisms, it is manifestthat a plurality of independently controlled motors might be utilizedfor actuating the various mechanisms, if desired,

VWithout departing from the broad features of my novel invention. Otherspecic features of construction might also be changed in many detailsWithout departing from the spirit and scope of my invention. I do nottherefore Wish to be understood as `limitiifig myself to the specificembodiment of the various novel features presented, excepting jin so faras particularly set forth in the 'following claims.

I claim as` my invention:

l. In a mining machine, a motor, a frame having a pair of tractiondevices spaced longitudinally of one side of said frame and normally insupporting engagement with the ground, and means for operating the same,a cutting element pivotally connected .to said frame intermediate saidtraction dehavingV a pair of traction devices spaced longitudinally atone side of said frame and normally 1n supporting engagement with theground, and means for operating the saine, a cuttingl element pivotallyconnected.

to said frame intermediate said traction devices to swing in ahorizontal plane, means operated by said motor for elevating saidtraction devices in a vertical plane parallel to the longitudinal axisof said frame to permit said cutting element to pass thereunder, andauxiliary supper `ing means earried by said cutting element and adaptedto support a portion of said frame when either o f said traction devicesis in elevated position. f

3. In a mining machine, a motor, a frame having a pair of tractiondevices spaced longitudinally of one ide of said frame and normally insupporting engagement withv the ground, a cutting element pivotallyconnected to said frame intermediate said trac-. tion devices to swingin ahorizontal plane, means for elevating and lowering said tractiondevices to permit said cutting element to pass thereunder and drivingconnections between said motory and said traction devices permitting thelatter to be selectively raised and instantaneously resume their'tractive elfort when lowered.

1i. In a mining machine, a motor, a frame having a pair of tractiondevices spaced longitudinallyl at one side of said frame and normally insupporting engagement with the ground, a cutting element pivotallyconnected to said frame intern'iediate said traction devn, means forraisino; and loiver said traction devices t-o permit said cuttingelement lo pass thereunder. driving connect ions between said motor an(said traction devices permitting the latter to be selectively raised andinstantaneously resume their tractive cti'ort when lowered, andauxiliary supporting means carried by said cutting element arranged tosupport a portion of said frame when the other of said traction devicesis in elevated position.

5. In a miningmachine, a frame, a motor, a pair of traction devicesspaced along one side of said frame Vand normally in supportingengagement with the ground, a cutting element pivotally connected tosaid frame on a vertical axis Within the boundaries of said tractiondevices, means affording independent vertical movement of said tractionlil devices to permit said cutting element to pass thereunder, said lastnamed means having operative connection Wit-h the motor to return saidtraction devices, when in raised position, into normal supportingengagement with the ground.

(S. in a mining machine, in combination, a frame, a motor, plurality oftsupporting members movable vertically with respect to said iframe andnormally adapted to support the latter, a cutting element pivotallysupported on said trame within the boundaries defined by said supportingmlen'ibers and adapted to extend beyond said boundaries, and mea-nsdriven by said motor for inde-l pendently operating said cutting elementand said supporting means to permit the cutting element to passthereunder.

7. ln a mining machine, in combination, a trame, a plurality ofsupporting members movable vertically with respect to said frame andnormally adapted to support the latter, a cutting element pivotallysupported on said frame within the boundaries deiined by said supportingmembers and adapted to extend beyond said boundaries, means forindependently operating said supporting means to permit the cuttingelement to pass thereunder, and an auxiliary supportwithin theboundaries defined by said supporting means as aforesaid, but extendingbeyond the center of gravity orn said machine in a direction toward oneof said supporting means When the latter is out of supportengagementwith the ground.

8. ln a mining machine, in combination, a iframe, a plurality ofsupporting members movable vertically with respect to said iframe andnormally adapted to support the latter, a cutting element pivotallysupported on said frame Within the boundaries dclined by said supportingmembers and adapted to extend beyond said boundaries, means iorindependently operating said supporting means to permit the (uittingelei'nent to pass thereunder, and an auxiliary support within theboundaries detined by said supporting means aforesaid, but extendingbeyond the center ot' gravity of said machine in a direction toward oneoit said supporting means when the latter is out 'of supportingengagement With the ground, said auxiliary support being movable withsaid cutting mechanism.

9. ln a mining machine, a trame, a motor, pair oi longitudinally spacedtraction devices normally in supporting' engagement with the ground, andhaving operative connection with said motor, a cutting element pivotallyconnected to said trame intermediate said traction devices, meansallerding vertical movement of one or more of said traction devices topermit said cut-ting elementto pass thereunder, said last-named meanshaving operative connection with the motor to return said tractiondevice, when in raised position, into normal supporting engagement withthe ground.

lO. ln a mining machine, the combination of a frame, a motor, a tractiondevice having operative connection with said motor and normally adaptedto engage the ground,

a cutting element pivotally mounted on said frame and extending beyondsaid traction device, means operatively connecting said motor with saidcutting element, power devices driven by said motor affording verticalmovement ot said traction device relative to said cutting element topermit the latter to swing on opposite sides oi said traction device,means associated With said last named power devices adapted to returnsaid traction device into normal supporting engagement with the ground,and an auxiliary support adapted to engage the ground While saidtraction device is in elevated p0- sition, said auxiliary support beingmovable with said cutting element.

ll. In a mining machine adapted for room and pillar mining, thecombination of a frame, a. kerf cutting element pivotally mountedcentrally or' said ira-me and adapted to laterally project from theinner side of said frame, a pair ot' power driven traction unitsoperable for feeding said machine along the lace ot the coal anddisposed at the inner side of said frame, and on advance and recedingsides oi said cutting element when the latterI is in laterally extendingposition, and an independently controlled traction device at the outerside of said frame operable for equalizing the reaction on the cutterbar during its feeding movement and thereby maintain the machine at thedesired angular' relation to the mine iace.

l2. In a mining machine adapted for room and pillar mining, thecombination of a frame, a keri cutting element pivotally mountedcentrally oit said iframe and projecting at the inner side or saidvframe, a pair oi power driven traction units operable ior feeding saidmachine along the lace of the coal and disposed at the inner side ofsaid trame, and on the advance and receding sides of said cuttingelement When the latter is in laterally extending position, and anindependently controlled differentially operable traction device at theouter side of said frame operable for equalizing the reaction on thecutter' bar during its 'feeding movement and thereby maintain themachin@ at the desired angular relation to the mine floor.

13. In a mining machine adapted for room and pillar mining, thecombination of a frame, a keri` cutting element pivotally mountedcentrally of said frame and projecting at the inner side of said frame,a pair of power driven traction units operable i'or feeding said machinealong the face of the coal and disposed at the inner sidel of lee1,664,666 i f 9V said frame, and on the advancing and receding sides ofsaid cutting element when the latter is in laterally extending position,and an independently controlled traction device at the outer side ofsaid frame operable for equalizing the reaction on the cutter bar duringits feeding movement and thereby maintain the machine at the desiredangular relation to the mine face, and a friction brake for controllingsaid last named traction device.

14;. In a mining machine, a frame, a cut'- ting element extendinglaterally from said frame. a. traction ldevice for feeding the machinebodily along the face of the coal to cut a lrerf, and supplementalfeeding means comprising aI draft cable Wound on the periphery of saidtraction device and adapted to be anchored to a fixed support in advanceof the machine.

15. In a mining machine, a frame, a cutting element extending laterallyfrom said frame, a traction device adjacent the inner or cutting sidethereof for feeding the machine bodily along the face of the coal to cuta kerf, and supplemental feeding means comprising a draft cable Wound-on the periphery of said traction device and adapted to be anchored toa fixed support in advance of the machine.

16. In a mining machine, a frame, a cutting element extending'laterallyfrom -intermediate the ends of said frame, a traction device. adjacentthe inner or cutting side thereof for feeding the machine bodily alongthe face of the coal to cut a. kerf, supplemental feeding meanscomprising a draft cable adapted to be anchored to a fixed support inadvance of the machine and'vvound on the periphery of said tractiondevice, and means voffset from said feeding means for retarding themovement of the outer end of the machine.

17. In a mining machine, a frame, a cutting element extending laterallyfrom intermediate the ends of said frame, a'traction device adjacent theinner or cutting side thereof for feeding the machine bodily along theface of the coal to cut a kerf, supplemental feeding means comprising adraft cable adapted to be anchored to a fixed' support in advance of themachine and Wound on the periphery of said traction device, apower-driven traction device Offset from said feeding means, and meansindependent of said feeding means for controlling said last namedtraction device.

18. In a mining machine, a frame, a cutting element extending laterallyfrom intermediate the ends of said frame, a traction device adjacent theinner or cutting side thereof for feeding the machine bodily along theface of the coal to cut a lrerf, supplemental feeding means comprising adraft cable adapted 'to be anchored to a fixed support in advance of themachine and Wound on the periphery of said traction device, a

ktraction device offset from said feeding piemental feeding meanscomprising a draft cable adapted to be anchored to a fixed sup-l port inadvance of the machine and Wound on the periphery of said tractiondevice, a traction device offset from said feeding means and manuallyoperated retarding kso means for controlling the movement of said lastnamed traction device independent of said feeding means.

20. In a mining machine, a frame, a cutting element extending laterallyfrom intermediate the ends of said frame, a traction device adjacent theinner 'or cutting side thereof for feeding the machine bodily along theface of the coal to cut a kerf, supplemental feeding means comprising adraft cable adapted to be anchored to a fixed support in advance of themachine and Wound on the periphery of said traction device, a tractiondevice offset from said feeding means, and a brake for controlling themovement of said last named traction device independent of said feedingmeans.

21. In a mining machine, a frame, acutting element extending laterallyfrom intermediate the ends of said frame, a traction device adjacent theinner or cutting side thereof for feeding the machine bodily valong, theface of the `coal to cut a kerf, supplemental feeding means comprising adraft cable adapted to be anchored to a fixed support in advance ofthemachine and Wound on the periphery of said traction device, apowerdriven traction .device-offset from said feeding means, and meansfor varying the driving speed of said last named traction deviceindependent of the vfeeding means.

22. In a mining machine, a frame, a cutting element extending laterallyfrom intermediate the ends of said frame, a traction device adjacent theinner or cutting side thereof for feeding the machine bodily along theface of the coal to cnt a kerf, supplemental feeding means comprising adraft cable adapted to be anchored to a fixed support in advance of themachine andWound on the periphery of said traction device, a powerdriventraction device offset from said feeding means, vand means for reversingsaid traction device respective to said feeding means, whereby they maybe driven either in the same or opposite directions.

23. In a mining machine, a frame, a ino- ,.tor, a ,plurality ot tractionwheels'adjustable vertically in several supporting positions respectiveto said trame and having continuous operative connection -vvitli saidmotor in the several permissible positions thereoi", a

Ohorizontally disposed turntable rotatably iiiountedon said trainewit-hin said wheels,

La` horizontally disposed cutter 'trame beneath said turntable, anauxiliary supporting pan beneath the inner end ot said cutter arm,

and normally maintained out ot supporting engagement with the ground bysaid traction Wheels, said turntable, cutter arin and pan being rigidlyconnected together.

24. In 4a mining machine, a traine, a inoltor, a plurality oiC tractionWheels adjustable ,vertically in several supporting positions respectiveto said traine, andv having continuous operative connection ivith .saidmotor in the several permissible positions, a hoi-i- Zontally disposedturntable rotatably mounted'on said 'traine Within said Wheels, a hori-Zontally disposed cutter arm beneath. said turntable, a sprocket shaftextending concentrically through said turntable, a chain sprocket onsaid shaft adjacent the inner end ot said cutter arm, a cutter chain andan auxiliary supporting pan beneath the inner end ,of said cutter armand said sprocket and-normally maintained out of supporting engagementWith the ground by said traction Wheels, .said turntable, cutter arm andpan being rigidly connected together.

25. In a mining machine, a traine, a inotoi, a plurality oi tractionWheels adjustable independently oit said'last named means for swingingsaid turntable angularly With respect to the frame to feed the cutterarin to the coal.

26. In a mining machine, a frame, a motor, a plurality of tractionWheels adjustable vertically in several supporting positions respectiveto saidfraine, a horizontally disposed turntable rotatably mounted onsaid frame Within said supports,a horizon- 4tally disposed cutter armbeneath said turntable, .a sprocket shaft extending concentricallythrough said turntable, a chain sprocket on said shaft adjacent theinner end of said cutter arm, ay cutter chain, apan beneath the kinnerend of said cutter arm and said sprocket, said turntable, cutter arm andpan being rigidly connected together, gear'- ing operatively connectedWithsaid motor V,for actuating said cutter chain, Aand Iother gearingoperatively connected With said motor for swinging said turntableangularly at a lower speed to feed the cutter -arm to the coal.

27. In a mining machine, a frame, Aa horilzoiit'ally disposed cutter armmovable into `various positions to cut at one side and at opposite endsol said trame, a pair oit longitudinally spaced rotatabletractiondevices capable ,of being driven in' either direction adjacent the inneror cutting side of said frame adapted to feed the ,cutter arin to thecoal, said traction devices being movable vertically with respect tosaid cutter arm to vperinit the latter to pass thereunder, andanindependently controlled traction unit capable vof being driven ineither direction offset and spaced laterally from said p airof tractiondevices.

2S. In a mining machine, a frame, `a hori- Zoiitally disposed cutter armmovable into various positions to cut at one side and at opposite endsof said frame, a pair of longitudinally spaced rotatable traction1devices capable ot being driven in either direction' adjacent therinner or cutting side of said trame adapted to feed `the cutterarm tothe coal, said traction devicesbeing movable vertically With respect tosaid lcutter arm to permit the latter tov pass thereunder, `a tractionunit capable of being driven in either direction offset and .spacedlaterally from said pair of traction devices, and controlling 4meansassociated WithsaidA traction unit for retarding the outer end of themachine While it isbeing ted tothe coal.

29. In a mining machine, a traine, a horizontally disposed vcutter armymovable into various positions to cut at one side and at opposite endsot said trame, a pair ot longitudinally spaced rotatable tractiondevices capable of being' driven iii' eitheivdirection adgacent theinner or cutting side of said frame adapted to feed the cutter arin tothe coal, said traction devices being movable vertically with respect tosaidcutter arm to permit the latter to pass thereunder, a traction unitcapable of being driven in either direction oitiiset and spacedlaterallyfrom said pair of traction devices, and maiiually controlled brakemechanism associated .With said traction inuit` for .retarding the outerend ot the machine While it is being ted to the coa-l. d

30. In a mining machine, a traine, a hori- Zontally disposed cutter armmovable into various positions to cut at one sideand at opposite ends ofsaid trame, a pair of longitudinally spaced rotatable traction devicescapable of being driven in either direction adjacent the inner orcutting side of said frame adapted to feed the cutter arm to the inocoal, said traction devices being movable vertically with respect tosaid cutter arm to permit the latter to pass thereunder, a traction unitcapable of being driven in'either direction offset and spaced laterallyfrom said pair of traction devices, and driving means for said tractionunit controlled independently of said feeding tract-ion devices.

3l. In a mining machine, a frame, a horizontally disposed cutter armmovable into various positions to cut at oneV side and at opposite endsof said frame, ak pair of longitudinally spaced rotatable tractiondevices adjacent the inner or cutting side of said frame adapted to feedthe cutter arm to the coal, said traction devices being movablevertically with respect to said cutter arm to permit the latter to passthereunder', a tractionunit offset and spaced laterally from said pairof traction devices, and reversible driving means for said traction unitcontrolled independently of said feeding traction devices.

32. In a mining machine, a frame, a hori- Zontally disposed cutter armmovable into various positions to cut one side and at opposite ends ofsaid frame, a pair of longitudinally spaced rotatable traction devicesadjacent the inner or cutting-side of said frame adapted to feed thecutter arm to the coal, said traction devices being movable verticallywith respect to said cutter arm to permit the latter to pass thereunder,a traction unit capable of being driven in either ydirection offset `andspaced laterally from said pair of traction devices, and differentialdriving` means for said traction unit controlled independently of saidfeeding traction devices.

33. In a mining machine, a frame, a horizontally disposed cutter armmovable into various positions to cut at one side and at opposite endsof said frame, a pair of longitudinally spaced rotatable tractiondevices adjacent the inner or cutting side of said frame adapted to feedthe cutter arm to the coal, said traction devices being movablevertically With respect to said cutter arm to permit the latter to passthereunder, a traction unit offset and spaced laterally from said pairof traction devices, and an auxiliary support movable with said cutterarm and adapted to maintain the equilibrium ofV the machine .While oneof said traction devices isin elevated position.

34. In a mining machine, a frame, a hori- Zontally disposed cutter armmovable into various positions to cut at one side and at opposite endsof said frame, a pair of longitudinally spaced rotatable tractiondevices adjacent the inner or cutting side of said frame adapted to feedthe cutter arm to the coal, said traction devices being movableverticallyy with respect to said cutter arm to permit the latter to passthereunder, a traction unit oifset and spaced laterally from said pairof traction devices, and a shoe movable With said cutter arm and adaptedto have sliding engagement with the ground to maintain the equilibriumof the machine While one of said traction devices is in elevatedposition.

35. Ina mining machine, a frame, a motor, a horizontally disposed cutterarm pivot-l ally mounted on said frame to swing in a complete circle andcut at both ends and sides of said frame, a plurality of tractiondevices for supporting and propelling said machine, each of saidtraction devices being adjustable vertically invseveral positions withrespect to said cutter arm to permit the `latter to pass thereunder, anddriving connections between said motor and said traction devicespermittingthe latter to be selectively raised and instantaneously`resume their tractive effort when lowere 36. In a mining machine adaptedfor use in room and pillar mining, a frame, a horizontally disposedcutter varm pivotally mounted on said frame adapted to extend asubstantially equal distance in advance of both ends thereof, means forsimultaneously feeding said cutter arm angularly to the coal, and meansfor feeding and guiding the machine bodily along the Working face, saidlast namedrmeans being reversible .to Withdraw the machine from the faceafter the cutter .arm has been moved from one end to the other throughan angle of approximately 180 degrees in making a-vcut at one side ofthe machine, and to feed and guide the machine in the opposite directionfor the next cut, With the cutter arm at the other side of the machine.

37. In a mining machine adapted for use in room and pillar mining, aframe, a horizontally disposed cutter arm pivotally mounted on saidframe adapted to extend in cutting position on all sides thereof, meansfor feeding said cutter arm angularly to the coal, and a plurality oflaterally spaced, in-

dependently controlled traction devices for feeding and guidingy themachine' bodily along the Working face, said traction devices beingreversible to Withdraw the machine from the face after the cut-ter armrhas been moved from one end to the `other through an angle ofapproximately 180 degrees in making a cut at one side of the machine,and

to feed and Guide the machine in the o `osite direction for the next cutwith the cutter arm at the other side of the machine and means formoving each of said traction devices vertically to permit said cutterarm to pass thereunder.

38. In a mining machine, a frame, a motor, a-horizontally disposedcutter bar pivotally mounted intermediate the ends of said frame toextend from both ends and at intermediate points about saidy frame, apair liso of rotatable traction devices adjacent vthe .cutting side ofsaid frame and having their axes spaced longitudinally of the pivotalpoint of said cutter arm whereby the latter, when positionedtransversely of the frame,

,extends laterally between within the vertical limits of said tractiondevices, and reversi- .ble connections between said motor and said.traction devices for driving the latter in .extend from both endsthereof and to cut at intermediate points about said frame, fourrotatable traction devices at the corners of `said frame, each pair ofsaid traction devices having their aXcs spaced longitudinally of.thepivotal point of said cutter arm on op posits sides thereof wherebythe latter eX- tends between `within the vertical limits of l.eachadjacent pair of traction devices when positioned at the sides or endsof said frame, and reversible connections between said motor and saidtraction devices for driving the latter in either direction. A

40. In a mining machine, a frame, four .vertically rmovable tractiondevices at opposite corners of said frame, a motor adjacent one vend ofsaid frame between two of said traction devices, a turntable rotatablymounted centrally of said frame and extending beneath said motor, acutting element -carried by said turntable, speed reducing gearing atthe endof the machine opposite said motor, said speed reducing mechanismhaving operative connection with said traction devices.

41. In a mining machine, a frame, four vertically movable tractiondevices at opposite corners of said frame, a motor adjacent `carried bysaid turntable, speed reducing gearing at the end of the machineopposite said motor, said speed reducing mechanism having operativeconnection with said traction wheels, and having an independently`controlled connection with said turntable to rotate the latter.

42. In a mining machine, a traine, iour vertically movable tractiondevices at opposite corners of said frame, a motor adjacent one end ofsaid frame between two of said traction devices, a turntable rotatably.mounted centrally of said frame and extending vbeneath said motor, acutting clement carried by said turntable, provided with a cutter chain,a drive shaft and sprocket for 4.said chain mounted concentrically ofsaid turntable and operatively connected with said motor, speed reducinggearing at the .end of the machine opposite said motor, said incassaspeed reducing mechanism havingvoperativo connect-ion with saidtractioiiwheels, and having an independently controlled connection withsaid turntable to rotate'the latter.

lf3. ln a mining machine, a frame, a cutting element extending laterallyfrom said frame, a traction wheel for feeding .the machine bodily alongthe face of the coal to cut a lreif, and supplemental Vfeeding meanscomprising a detachable draft cable Wound on the periphery of saidtraction` wheel and adapted to be anchored to a fixed support in advanceof the machine. dei. In a mining machine, a frame provided with suitablecutting mechanismifoi cutting a lrerf, a traction wheel for feeding themachine bodily along the face; of ,theV

coal, a motor, and a spur gear mounted in said frame and meshed with .arack Vformed in the outer periphery of said traction wheel, said gearhaving operative connection'with the motor, and verticallyadjustablesup-V porting means for said tractionwheels pivotallyconnected to said frame concentric with said gear.

45. ln a mining'inachine, a frame provided with suitable cuttingmechanism ,for cutting a lreif, a traction wheel y,for feeding themachine bodily along theface ofthe coal, a motor, a spur gear mounted in.said frame and meshed with a. rack formed in the outer periphery ofsaid traction wheel, said gearing having operative connection with themotor, and supplemental feeding means comprising a draft cable adaptedtobe anchored to a fixed support in advance of the machine and wound onthe outer periphery of said traction wheel adjacent said rack.

46. ln a mining machine, a frame .provided with suitable .cuttingmeehanismf-for cutting a kerf, a traction wheel for feeding the machinebodily along the face ofV the a rack formed in the periphery of saidtraction wheel and ineshed with .said gear, a

series of projections also formed about said coal, a driving gearmounted in said frame,

periphery, and supplemental feeding means comprising a draft cable woundabout said periphery adjacent said racl and said `series of projectionsand adapted to be anchor-ed to a fixed support in advance of themachine.

4.7. In a mining machine, a frame, .a plurality of traction wheels,means for controlling said. traction wheels to guide the mining machineduring its cutting operation, and a draft cable detachably connectedr toand wound about the periphery of one vot said traction wheels andadapted tofafiford additional draft to the latter.

48. In a mining machine, a frame, a cutting element pivotallymountedvbeneath said frame to cut a substantially horizontal keifadjacent the mine fioor,.a plurality of power actuated traction wheelsand an intermediate auxiliary support adapted to engege'the lli groundduring a portion of the cutting operation, and means for raising andlowering said frame with respect to said wheels to permit increasedclearance of said cuttingv element and support with respect to the minefloor while the machine is being transported from place to place.

49. In a mining machine, a frame, a cutting element pivotally mountedbeneath said frame to cut a substantially horizontal lrerf adjacent themine floor, a pan iii-:ed beneath the inner end of said cutting elementand adapted to provide an auxiliary support for said frame during aportion of the cutting operation, a plurality of power actuated tractionwheels adapted to support said machine, and means for raising andlowering said frame with respect to said wheels to permit increasedclearance of said cutting element and said pan with respect to the minefloor while the machine is being transported from place to place on saidtraction wheels.

50. In a mining machine, a motor, a frame, a cutting element pivotallymounted beneath said frame to swing in a horizontal plane, a pluralityof supporting arms pivotally mounted on axes arranged transversely ofsaid frame to swing on a vertical plane, traction wheels journaled insaid arms, and means for pivotally swinging said arms to selectivelymove said traction wheels vertically above the level of said cuttingelement, and power connections between said motor and said tractionwheels in all permissible positions thereof.

5l. In a mining machine, a frame, a cutting element pivotally mountedbeneath said frame to swing in a horizontal plane, a plurality ofsupporting arms pivotally mounted on said frame to swing in a verticalplane, traction wheels journaled in said arms, and motor driven meansfor pivotally swinging said arms to move said traction wheels verticallyabove the level of said cutting element.

62. In a mining machine, a frame, a cutting element pivotally mountedbeneath said frame to swing in a horizontal plane, aV plurality ofsupporting arms pivotally mounted on said frame to swing in a verticalplane, traction wheels journaled in said arms, means for pivotallyswinging said arms to move said traction wheels vertically above thelevel of said cutting element, and motor driven gears for driving saidtraction wheels mountedy to rotate concentrically with said pivotedarms, and having operative connection with said traction wheels in allpositions of the latter. y

58. In a mining machine, a frame, a cutting element pivotally mountedbeneath said frame to swing in a horizontal plane, a pair of tractionunits on opposite sides of said frame, each comprising a pair of armspivotally mounted on said frame to swing in a vertical plane, a tractionwheel journaled on each rotatably mounted concentric with one f of saidarms and having operative connection with its respective wheel, both ofsaid spur gears beingV connected to drive rthe wheels at uniform rspeedand in the saine direction.

54. In a mining machine, a frame7 a cutting element pi'votallyv mountedon said frame to swing in a horizontal plane, a pair of traction unitson opposite sides of said frame, each comprising a pair of armspivotally mounted on said frame to swing in a vertical plane, atractionvwheel journaled on each of said arms, power actuated mechanismfor swinging each of said arms independently of the others to move itsrespective traction wheel vertically respective to said frame, and otherpower actuated mechanism for driving said traction unit including a pairof gears each rotatably mounted conceny tric with one of said arms, andhaving operative connection with its respective wheel, both of saidgears being connected to drive the wheels at uniform speed and in thesame direction.

55. In a mining machine, a frame, a cutting element pivotally mounted onsaid frame to swing in a horizontal plane, a pair of traction units onopposite sides of said frame, each comprising a pair of longitudinallydisposed arms' pvotally mounted on said frame to swing in a verticalplane, a traction wheel journaled on each of said arms, power actuatedmechanism'for swinging each of said arms independently of others to moveits respective traction wheel vertically respective to said frame, andother traction unit controlled independently of the other unit, andincluding a pair of gears each rotatably mounted concentric with one ofsaid arms, and having operative connection with its respective wheel,both of said gears being connected to driveA the wheels at uniform speedand in the saine direction.

56. In a mining machine, the combination of a frame, a cutting elementpivotally mounted beneath said frame, a plurality of power actuatedtraction devices adapted normally to propel the machine along the minefloor, means for raising and lowering said traction devices verticallyrelative to said frame an auxiliary, centrally disposed support carriedby said frame, and means on said traction devices adapted to engage atrack.

57. In a mining machine adapted for room power actuated mechanism fordriving said Y and pilla'r mining, a frame',` a motor, a kerf cuttingelement pivotally mounted`- centrally of said frame to' swing in ahorizontal pla-ne, a plurality of traction devices adapted to supportthe machine and feed the cutting LeeaeeeV ed to support the machine andfeed; the cut-` ting element to thefcoal by tractiveieffort While themachine is being moved bodily, along the Working face, Vpowerconnections between said motor and said traction devices includingchange-speed transmission devices aiiording selective movement of saidmachine at a predetermined cutting speed orat a higher moving speed fortransporting the machine from place to place in the mine', and'meansdriven by said motor 'for selec-4 tively raising said traction devicesout of: supporting engagement with the ground to permit said cuttingelement to swing. thereunder. f.

Signed at Chicago,- in thecounty oi'l Cook: and State of Illinois, thissecondf'dayoV June, 1922. ,i CHARLES DAVIS;

